When I went camping out in Dripping Springs, the place my boyfriend and I stayed had a beautiful butterfly garden. As we were walking to go get firewood, we noticed an injured butterfly on a gravel path far from the garden. This little Pipevine Swallow wasn’t flying well on his own, but we carried him to a plant inside the garden in hopes that he would be safer there. The caterpillars of this species feed on the Aristolochia plant species, making them poisonous as both larvae and adults, which offers them protection.
http://www.inaturalist.org/observations/5171394